Digital Commons Network^™

Dartcvl: The Dartmouth C Vector Library, Thomas H. Cormen, Sumit Chawla, Preston Crow, Melissa Hirschl, Roberto Hoyle, Keith D. Kotay, Rolf H. Nelson, Nils Nieuwejaar, Scott M. Silver, Michael B. Taylor, Rajiv Wickremesinghe

Computer Science Technical Reports

As a class project, we implemented a version of CVL, the C Vector Library, on a DECmpp 12000/Sx 2000, which is equivalent to the MasPar MP-2 massively parallel computer. We compare our implementation, DartCVL, to the University of North Carolina implementation, UnCvl.

DartCVL was designed for the MP-2 architecture and UnCvl was designed for the MP-1. Because the MasPar MP-1 and MP-2 are functionally equivalent, both DartCVL and UnCvl will run on either. Differences in the designs of the two machines, however, may lead to different software design decisions. DartCVL differs from UnCvl in two key ways. First, DartCVL uses …

A Study Of Voluntary Participation In Computer User Groups, Alan Engels

Electronic Theses & Dissertations

The purpose of this study was to determine ways to increase participation of members in Computer User Groups. The problem addressed was that a small select group, less than ten percent, in the Parsons Apple/Macintosh Users Group was doing ninety-five percent or more of the work. If this scenario does not change soon, the overworked and overburdened select few may suffer burnout and quit. Case in point, Joplin, MO, had a large Computer User Group, but about seven years ago, it vanished when the select few refused to serve anymore. The same process of decay and erosion has happened in …

Idea Analysis For The Development Of Clinical Trial Strategies, Roberta S. Horowitz

CCAC Theses and Dissertations

Idea Analysis was investigated to determine its ability to organize scientific information and explain the results of specialists' deliberations in designing new clinical trials. Ideas have long been recognized as the engine of creativity. By focusing on the capture of ideas from the scientific literature, idea analysis procedures enable the arrangement of the information into forms consistent with those developed by subject specialists. The most obvious example is the concept structure. Ideas containing a common frequently occurring term/phrase can be depicted as a primary node in the concept network. Related terms will appear as elements associated with that node. Ideas …

Large-Scale Client/Server Migration Methodology, A. Steven Krantz

CCAC Theses and Dissertations

The purpose of this dissertation is to explain how to migrate a medium-sized or large company to client/server computing. It draws heavily on the recent IBM Boca Raton migration experience. The client/server computing model is introduced and related, by a Business Reengineering Model, to the major trends that are affecting most businesses today, including business process reengineering, empowered teams, and quality management. A recommended information technology strategy is presented. A business case development approach, necessary to justify the large expenditures required for a client/server migration, is discussed. A five-phase migration management methodology is presented to explain how a business can …

A Taxonomy Of Workgroup Computing Applications, Warren Von Worley

CCAC Theses and Dissertations

The goal of workgroup computing is to help individuals and groups efficiently perform a wide range of functions on networked computer systems (Ellis, Gibbs, & Rein, 1991). Early workgroup computing tools were designed for limited functionality and group interaction (Craighill, 1992). Current workgroup computing applications do not allow enough control of group processes and they provide little correlation between various workgroup computing application areas (Rodden and Blair, 1991). An integrated common architecture may produce more effective workgroup computing applications. Integrating common support functions into a common framework will avoid duplication of these functions for each workgroup computing application (Pastor & …

Transient Data Sharing Among Mobile Programs, Jerome Plun, Gruia-Catalin Roman

All Computer Science and Engineering Research

Mobile computing represents a major point of departure from the traditional distributed computing paradigm. The potentially very large number of independent computing units, a decoupled computing style, frequent disconnections, continuous position changes, and the location-dependent nature of the behavior and communication patterns present designers with unprecedented challenges in the areas of modularity and dependability. This paper describes a modular approach to specifying and reasoning about of mobile computing. Its novelty rests with the notion of allowing transient (location-dependent) data sharing among programs which move in space. The notation is a direct extension of that used in UNITY and reasoning about …

A Survey Of Network Signaling, Dakang Wu

All Computer Science and Engineering Research

Abstract Network signaling is the process of transferring control information among components of a communication network to establish, maintain, and release connections, and to pass the network management information. The rapid evolution in the field of telecommunications has led to the rapid evolution of network signaling. In this paper, we review the evolution of network signaling. We emphasize the concepts and protocols used in modern fast packet switching networks especially in emerging ATM networks.

An Efficient Signaling Structure For Atm Networks, Dakang Wu

All Computer Science and Engineering Research

As ATM becomes widely accepted as the communication standard for high speed networks, the signaling system structure and protocols that support ATM become more and more important. To support existing, future and unknown applications, the signalign system has to be very flexible and efficient. In this paper we define the signaling problem, present several possible signaling system structures, compare the advantages and disadvantages of these systems, and then we propose a new signaling system structure. The fundamental idea of the new signaling system is the logical separation of the signaling system structure from the underlying communication network, even though they …

Synchronized Data Objects, Marin Bezic

All Computer Science and Engineering Research

Synchronized Data Objects (SDOs) are presented as a method of encapsulating, in the datatype definition, synchronization protocols that are used to control information exchange. SDOs are presented in the context of I/O abstraction, a programming model that seeks to separate communication from computation in order to support dynamic end-user configuration of distrivuted applications. SDOs can be used to implement a variety of synchronization paradigms, including remote invalidation, demand-driven data streams, remote procedure call, and promises. An implementation of SDOs is described in the context of The Programmers' Playground, a distributed application development environment that supports the I/O abstraction programming model. …

Distributed Debugging With I/O Abstraction, Andrew S. Koransky

All Computer Science and Engineering Research

This thesis presents a simple, yet powerful, set of mechanisms for testing and debugging distributed applications consisting of modules that communicate through well-defined data interfaces. The tools allow default or programmer-defined functions to be attached to various communication events so that particular data values at interesting points in the program are made available for testing and debugging. The debugging status of each component of the communication interface can be controlled separately so that various debugging information can be turned on and off during program execution. By attaching breakpoints to programmer-defined fucntions in a standard debugger, fine-grained examination of each module …

Reasoning About Program Interactions In The Presence Of Mobility, Gruia-Catalin Roman, Peter J. Mccann

All Computer Science and Engineering Research

Mobile computing is emerging as an important new paradigm which has the potential to reshape our thinking about distributed computation. Mobility has far-reaching implications on what designers and users can assume about communication patterns, resource availability, and applciation behaviors as components move from one location to another while joining or leaving groups of other components in their vicinity. New distributed algorithms are likely to be required as the nature of applications shifts with the emergence of this new kind of computing environment. Formal methods have an important role to play in the midst of these developments both in terms of …

Assertional Reasoning About Pairwise Transient Interactions In Mobile Computing, Gruia-Catalin Roman, Peter J. Mccann, Jerome Plun

All Computer Science and Engineering Research

Mobile computing represents a major point of departure from the traditional distributed computing paradigm. The potentially very large number of independent computing units, a decoupled computing style, frequent disconnections, continuous position changes, and the location-dependent nature of the behavior and communication patterns of the individual components present designers with unprecedented challenges in the areas of modularity and dependability. This paper describes two ideas regarding a modular approach to specifying and reasoning about mobile computing. The novelty of our approach rests with the notion of allowing transient interactions among programs which mobe in space. In this paper we restrict our concert …

Design Of A Tool For Rapid Prototyping Of Communication Protocols, Aniruddha Gokhale, Ron Cytron, George Varghese

All Computer Science and Engineering Research

We present a new tool for automatically generating prototypes of communication protocols on a wide variety of platforms. Our goal is to reduce design time, enhance portability, and accommodate optimizations automatically. Users of the tool are required to provide an abstract implementation of the protocol in C++ without worrying about the underlying operating system specific system calls. Instead, the user employs high-level interface functions provided by the tool to interact with the underlying operating system. Users also need not worry about complex packet formats that involve fields of various bit and byte lengths. Instead, they use simple C/C++ struct declarations …

Parallel Remapping Algorithms For Adaptive Problems, Chao Wei Ou, Sanjay Ranka

Northeast Parallel Architecture Center

In this paper we present fast parallel algorithms for remapping a class of irregular and adaptive problems on coarse-grained distributed memory machines. We show that the remapping of these applications, using simple index-based mapping algorithm, can be reduced to sorting a nearly sorted list of integers or merging an unsorted list of integers with a sorted list of integers. By using the algorithms we have developed, the remapping of these problems can be achieved at a fraction of the cost of mapping from scratch. Experimental results are presented on the CM-5.

Communication Strategies For Out-Of-Core Programs On Distributed Memory Machines, Rajesh Bordawekar, Alok Choudhary

Northeast Parallel Architecture Center

In this paper, we show that communication in the out-of-core distributed memory problems requires both inter-processor communication and file I/O. Given that primary data structures reside in files, even communication requires I/O. Thus, it is important to optimize the I/O costs associated with a communication step. We present three methods for performing communication in out-of-core distributed memory problems. The first method, termed as the “out-of-core“communication method, follows a loosely synchronous model. Computation and Communication phases in this case are clearly separated, and communication requires permutation of data in files. The second method, termed as”demand-driven-in-core communication” considers only communication required of …

The Use Of The National Information Infrastructure And High Performance Computers In Industry, Geoffrey C. Fox, Wojtek Furmanski

Northeast Parallel Architecture Center

We divide potential NII (National Information Infrastructure) services into five broad areas: Collaboration and televirtuality; InfoVISiON (Information, Video, Imagery, and Simulation on Demand), and digital libraries; commerce; metacomputing; WebTop productivity services. The latter denotes the broad suite of tools we expect to be offered on the Web in a general environment we term WebWindows. We review current and future World Wide Web technologies, which could underlie these services. In particular, we suggest an integration framework WebWork for High Performance (parallel and distributed) computing and the NII. We point out that pervasive WebWork and WebWindows technologies will enable, facilitate and substantially …

Cluster Computing Review, Mark Baker, Geoffrey C. Fox, Hon W. Yau

Northeast Parallel Architecture Center

In the past decade there has been a dramatic shift from mainframe or ‘host−centric’ computing to a distributed ‘client−server’ approach. In the next few years this trend is likely to continue with further shifts towards ‘network−centric’ computing becoming apparent. All these trends were set in motion by the invention of the mass−reproducible microprocessor by Ted Hoff of Intel some twenty−odd years ago. The present generation of RISC microprocessors are now more than a match for mainframes in terms of cost and performance. The long−foreseen day when collections of RISC microprocessors assembled together as a parallel computer could out perform the …

Exploiting High Performance Fortran For Computational Fluid Dynamics, Volume 919, Ken Hawick, Geoffrey C. Fox

Northeast Parallel Architecture Center

We discuss the High Performance Fortran data parallel programming language as an aid to software engineering and as a tool for exploiting High Performance Computing systems for computational uid dynamics applications. We discuss the use of intrinsic functions, data distribution directives and explicitly parallel constructs to optimize performance by minimizing communications requirements in a portable manner. In particular we use an implicit method such as the ADI algorithm to illustrate the major issues. We focus on regular mesh problems, since these can be efficiently represented by the existing HPF definition, but also discuss issues arising from the use of irregular …

High Performance Distributed Computing, Geoffrey C. Fox

Northeast Parallel Architecture Center

High Performance Distributed Computing (HPDC) is driven by the rapid advance of two related technologies -- those underlying computing and communications, respectively. These technology pushes are linked to application pulls, which vary from the use of a cluster of some 20 workstations simulating fluid flow around an aircraft, to the complex linkage of several hundred million advanced PCs around the globe to deliver and receive multimedia information. The review of base technologies and exemplar applications is followed by a brief discussion of software models for HPDC, which are illustrated by two extremes -- PVM and the conjectured future World Wide …

Basic Issues And Current Status Of Parallel Computing -- 1995, Geoffrey C. Fox

Northeast Parallel Architecture Center

The best enterprises have both a compelling need pulling them forward and an innovative technological solution pushing them on. In high-performance computing, we have the need for increased computational power in many applications and the inevitable long-term solution is massive parallelism. In the short term, the relation between pull and push may seem unclear as novel algorithms and software are needed to support parallel computing. However, eventually parallelism will be present in all computers -- including those in your children's video game, your personal computer or workstation, and the central supercomputer.

Effects Of Technology Mapping On Fault Detection Coverage In Reprogrammable Fpgas, Kevin A. Kwiat, Warren Debany, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

Although Field-Programmable Gate Arrays (FPGAs) are tested by their manufacturers prior to shipment, they are still susceptible to failures in the field. In this paper, test vectors generated for the emulated (i.e., mission) circuit are fault simulated on two different models: the original view of the circuit, and the design as it is mapped to the FPGA's logic cells. Faults in the cells and in the programming logic are considered. Experiments show that this commonly-used approach fails to detect most of the faults in the FPGA.

Graduate Bulletin, 1995-1996 (1995), Moorhead State University

Graduate Bulletins (Catalogs)

No abstract provided.

Shape Reconstruction From Shading Using Linear Approximation, Ping Sing Tsai

Retrospective Theses and Dissertations

Shape from shading (SFS) deals with the recovery of 3D shape from a single monocular image. This problem was formally introduced by Horn in the early 1970s. Since then it has received considerable attention, and several efforts have been made to improve the shape recovery. In this thesis, we present a fast SFS algorithm, which is a purely local method and is highly parallelizable. In our approach, we first use the discrete approximations for surface gradients, p and q, using finite differences, then linearize the reflectance function in depth, Z ( x , y), instead of p and q. This …

Critical Success Factors For Organizational Case Success, Chad Strauss

Presidential Scholars Theses (1990 – 2006)

Practitioners and researchers have suggested that Computer Aided Software Engineering (CASE) technology can significantly improve the productivity of systems analysts and the quality of systems development. Before CASE can succeed, however, specific components must exist. This paper explores CASE and the components necessary for its widespread acceptance and use within information systems departments. Specifically, this paper will examine the systems development life cycle (SDLC), the possible benefits of CASE, the current state of CASE, critical success factors for CASE, and finally CASE use.

Analysis And Extension Of Model-Based Software Executives, Keith E. Lewis

Theses and Dissertations

This research developed a comprehensive description of the simulation environment of Architect, a domain-oriented application composition system being developed at the Air Force Institute of Technology to explore new software engineering technologies. The description combines information from several previous research efforts and Architect's source code into a single, comprehensive document. A critical evaluation of the simulation environment was also performed, identifying improvements and modifications that enhance Architecture's application execution capabilities by reducing complexity and execution time. The analysis was then taken one step further and presented extensions to the current simulation environment. The extensions included investigating the feasibility of mixed-mode …

Interaction And Interdependency Of Software Engineering Methods And Visual Programming, Robert A. Touchton

UNF Graduate Theses and Dissertations

Visual Programming Languages and Visual Programming Tools incorporate non-procedural coding mechanisms that may duplicate, or perhaps even conflict with, the analysis and design mechanisms promulgated by the mainstream Software Engineering methodologies. By better understanding such duplication and conflict, software engineers can take proactive measures to accommodate and, ideally, eliminate them. Better still, there may be opportunities for synergy that can be exploited if one is looking for them.

This research explored, documented and classified the interactions and interdependencies, both positive (synergies) and negative (conflicts), between two closely related and rapidly evolving Computer Science subdisciplines: software engineering and visual programming. A …

Towards An Ontology Of Problems, Martin Zwick

Complex Systems Faculty Publications and Presentations

Systems theory offers a language in which one might formulate a metaphysics (or more specifically an ontology) of problems. This proposal is based upon a conception of systems theory shared by von Bertalanffy, Wiener, Boulding, Rapoport, Ashby, Klir, and others, and expressed succinctly by Bunge, who considered game theory, information theory, feedback control theory, and the like to be attempts to construct an "exact and scientific metaphysics." Our prevailing conceptions of "problems" are concretized yet also fragmented and in fact dissolved by the standard reductionist model of science, which cannot provide a general framework for analysis. The idea of a …

Reliable Stream Transmission In Mobile Computing Environments, Houzhi Xu, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Brokered Collaborative Infrastructure For Cscw, Chandrajit Bajaj, Peinan Zhang, Alok R. Chaturvedi

Department of Computer Science Technical Reports

No abstract provided.

Parallel Test Generation With Low Communication Overhead, Sivaramakrishnan Venkatraman, Sharad C. Seth, Prathima Agrawal

School of Computing: Conference and Workshop Papers

In this paper we present a method of parallelizing test generation for combinational logic using boolean satisfiability. We propose a dynamic search-space allocation strategy to split work between the available processors. This strategy is easy to implement with a greedy heuristic and is economical in its demand for inter-processor communication. We derive an analytical model to predict the performance of the parallel versus sequential implementations. The effectiveness of our method and analysis is demonstrated by an implementation on a Sequent (shared memory) multiprocessor. The experimental data shows significant performance improvement in parallel implementation, validates our analytical model, and allows predictions …